Reinforced plastic materials, particularly fiber-reinforced plastic materials, have been prepared by various procedures in which the plastic is pre-impregnated into a fibrous reinforcement. The plastic used as the continuous phase is usually of the thermoset type with chopped or relatively short reinforcing fibers distributed uniformly in the plastic matrix. A limited number of thermoplastic-based reinforced systems are known, for instance, as a liquid plastic added to a fibrous bat or in a film stacking process in which alternating layers of fibrous reinforcement and thermoplastic film are plied one atop the other then consolidated with heat and pressure to form a consolidated laminated article.
To the best of our knowledge, a fiber reinforced thermoplastic prepreg material containing a substantial, functionally significant amount of long fiber reinforcement presenting a smooth, glossy, cosmetically attractive surface has not been described by a thermoforming process. The thermoplastic properties of the prepreg material allow forming and processing procedures not possible with thermosetting reinforced materials. The fiber reinforced thermoplastic prepreg materials of this invention may be thermoformed into a final shape with heat and pressure in a single step or previously consolidated prepregs may be heated and formed in conventional (unheated) metal forming presses.